Correction to This Article
Earlier versions of this article, including in the print edition of The Washington Post, incorrectly said that the vote of 71 to 26 was seven votes more than the two-thirds required for Senate passage of the New START nuclear arms pact with Russia. With 97 senators voting, 65 votes were necessary for a two-thirds majority, so the tally was six more than required. This version has been corrected.

Arms treaty approval a win for Obama, but GOP critics are gaining momentum

Now the Russian leader wanted to know whether the treaty was in trouble in the U.S. Senate.

"President Medvedev was wondering what the election would mean, in terms of ratification. It's fair to say they were nervous," said one U.S. official who was in the meeting.

"That had an impression" on Obama, the official said, speaking on the condition of anonymity.

On the plane back to Washington, Obama told aides he was determined to get the New Strategic Arms Reduction Treaty (START) through the Senate by year's end. "We've got to go for it," the official recalled Obama saying.

The next few weeks marked a remarkable resurgence for a White House demoralized by Democratic losses in the elections. On Wednesday, the Senate approved New START by a vote of 71 to 26, six more than the 65 required for ratification but well short of the resounding approval that most nuclear-arms treaties have received.

Republican critics cited concerns about the treaty's language on missile defense, verification and other issues. But what appeared to tip a number against the treaty was Senate Majority Leader Harry M. Reid''s (D-Nev.) decision to shoehorn issues dear to the Democratic base into the waning days of the session, which infuriated Republicans.

The White House strategy ultimately proved successful, but the rise of partisan passions may complicate Obama's future arms-control efforts.

Lining up the GOP

Even before his Nov. 13 meeting with Medvedev, Obama had turned his attention away from the midterm elections and to New START. On Nov. 5, while flying to India, he gathered national security adviser Thomas E. Donilon, press secretary Robert Gibbs and senior aides Valerie Jarrett and Ben Rhodes to ensure they had a strategy to win ratification of the treaty in the lame-duck session.

They did - or so they thought.

For months, Vice President Biden had been coordinating negotiations with Sen. Jon Kyl (Ariz.), the point man on the Republican side, who was demanding extra money to fix up the aging U.S. nuclear weapons complex as a condition of giving Republicans the green light to approve New START.